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2 years ago

45 The mass of an unidentified metal sphere is 133 grams. Students determine the

Chemistry

1 answer:

Lisa [10]2 years ago

7 0

Answer:

D Cobalt

Explanation:

The volume of the sphere is 40 -25 = 15 cm^3

Density = mass/volume = 133 gm / 15 cm^3 = 8.87 gm/cm^3

which corresponds to Cobalt from the chart

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5. Geologists think that the inner and outer cores of Earth consist of iron and nickel.

wolverine [178]

Answer:

is this true/false? if so its true.

Explanation:

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2 years ago

Why is conical flask used in the freezing point of naphthalene activity?

SpyIntel [72]

Answer:

D. To ensure the cooling process is not affected by surrounding temperature

Explanation:

The conical flask acts as a temperature jacket.

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2 years ago

In Universe , recently discovered by an intrepid team of chemists who also happen to have studied interdimensional travel, quant

tiny-mole [99]

Answer:

Check the explanation

Explanation:

When talking about our universe there are 5 d orbitals. The element of first transition series moves away from the universal principles of Hund's rule and Aufbav's principle. So in order to attain stability these elements tend to form half or full filled orbitals.

In our universe the ground state electronic configuration of sixth transition metal, Iron (Fe) : [Ar] $3d^{6} 4s^{2}$

and the electronic configuration of seventh transition metal, Cobalt (Co) : [Ar] $3d^{7} 4s^{2}$

=================================

In universe L there are seven orbitals.

Ground state electronic configuration of sixth and seven transition element.

Sixth transition metal: [Ar] $3d^{7} 4s^1 or [X] 3d^{7} 4s^1$

Seventh transition metal: [Ar] $3d^{7} 4s^{2}or [X] 3d^{7} 4s^{2}$

7 0

3 years ago

Cobalt-63 has a half-life of 5.3 years. If a pellet that has been in storage for 15.9 years contains 40.0g of Cobalt-63, how muc

Cerrena [4.2K]

Answer:

320 g

Step-by-step explanation:

The half-life of Co-63 (5.3 yr) is the time it takes for half of it to decay.

After one half-life, half (50 %) of the original amount will remain.

After a second half-life, half of that amount (25 %) will remain, and so on.

We can construct a table as follows:

No. of Fraction Mass

half-lives t/yr Remaining Remaining/g

0 0 1

1 5.3 ½

2 10.6 ¼

3 15.9 ⅛ 40.0

4 21.2 ¹/₁₆

We see that 40.0 g remain after three half-lives.

This is one-eighth of the original mass.

The mass of the original sample was 8 × 40 g = 320 g

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3 years ago

The model below shows an atom of an element. 9 light grey and 8 dark grey balls sit at the center with 2 concentric black rings

aleksley [76]

Answer:

sorry if this is a bit late but i know what your talking about and your answer would be 8

stay happy!!

3 0

3 years ago

Read 2 more answers